The fourth nature of the contemporary city: from Rio de Janeiro to Seattle, Washington

The concept of ‘fourth nature’, intended as the nature of the city, will be developed through an examination of the urban forest projects of two important experiences in modern landscape design: Roberto Burle Marx’s Aterro do Flamengo in Rio de Janeiro, and the Seattle Freeway Park by Lawrence Halprin & Associates. These works suggest an entirely new project for public space — intended as the transposition of an original landscape and a native ecology, such as the Floresta da Tijuca in Rio de Janeiro, and the original ‘old growth’ forest of Seattle. The definition of ‘fourth nature’ is added to the three different categories of nature as described in the literature of landscape studies: a ‘first nature’, seen as wild, luxuriant and uncontaminated, is connected to a ‘second nature’ identified by Cicero as the cultural landscape that is productive and shaped by human activity (agriculture, urban development, roads etc.). To these two definitions the garden can be appended as a ‘third nature’, shaped for aesthetic purposes and designed as a combination of nature and culture. The urban question is thus enhanced with a new poetic that, following the idea of ‘fourth nature’, promotes a harmonious growth of the city wherein its natural dimension bestows a new and more effective meaning in the form of open public space. This is evidently not the same idea of ‘fourth nature’ as described by John Dixon Hunt, regarding the symbolic and ideal spaces in landscape design generated by literature on gardens, and his considering it as the ‘verbal, conceptual existence beyond its practical aspects’. Connected to the definition of ‘fourth nature’, there is also the ‘four natures approach’ that is applied to urban reality by Ingo Kowarik as a conceptual framework in which to structure and communicate a variety of green spaces within urban borders. In this case the ‘fourth nature’ identified by the German landscape ecologist includes the spontaneous plant-life that develops in brownfield sites in abandoned areas of the postindustrial cites, which is different from an image of nature incorporated in the city and from the city that I intend to present with this article. What distinguishes this new poetics of nature is its basis in a recognized ecological paradigm, and its capacity to shed light on a new functional aesthetic that can be applied in the urban landscape. My research centers on a renewed relationship between the city and nature starting with the evaluation of the effective natural scale of an urban project, as a specific model in the development of the contemporary city based on an awareness of Ecology’s role in the processes of urban planning. The urban scene becomes a field of experimentation of strongly innovative approaches that are capable of evoking natural processes, while validating formal and ideological reflections of a profound ecological significance. In particular, the Parque do Flamengo in Rio de Janeiro at the beginning of the 1960s and the Freeway Park in Seattle one decade later, both introduce unprecedented categories of places that become episodes of exceptional relevance for the originality of their formation, their particular amplification of the effects of nature, and the value they hold in the culture of the landscape project.